Illuminated switch



March 30, 1954 E V. SUNDT ILLUMINATED SWITCH Filed NOV. 18, 1950 Arramvzys.

INVENTOR.

Patented Mar. 3Q, 1954 ILLUMINATED SWITCH Edward V. Sundt, Wilmette, Ill., assignor toSundt Engineering Company, Chicago, Ill., acompany of Illinois Application November 18, 1950, Serial No. 196,432

This invention relates to illuminated switches and particularly toilluminated doorbell switches.

Previous attempts to illuminate switches of this kind have proven unsuccessful largely because of the wide range of voltages encountered in service. Two lamps have been employed to cover these voltage ranges, usually connected in parallel forthe lower half of the voltage range and in series for the higher half. Also, resistors have been employed in series with one or more lamps. This latter practice is wasteful of current since the energy dissipated in the resistor is wasted. Since the lamp or lamps are oonnected across the .open doorbell switch and in series with the bell or chimes, the latter are sometimes inadvertently operated.

The principal object of this invention is to provide an improved illuminated switch wherein the above weaknesses .are eliminated, wherein a single lamp may be used for wide voltage ranges, wherein the necessity for resistors is eliminated, which is simple and inexpensive to manufacture and install, which has practically unlimited life at service voltages, and which carries indicia which maybe readily read in the dark.

In carrying out this object of the invention, the illuminated switch includes a base, switch means carried by the base, a switch key of light transmitting material for operating the switch means, and a lamp connected in parallel to the switch means and located beneath the switch key for illuminating the same. The switch means may be located in series with the bell or chimes for operating the same when the switch key is depressed.

Preferably, the lamp is a tungsten coiled-coil filament lamp operating between 1900 K. and 900 K. at'voltages between 24 volts and 10 volts respectively. The lamp gives adequate light at 10 volts and still operates at a sufficiently low temperature at 24 volts to provide a calculated life of at least '10 years at such higher voltage. The lamp filament itself acts as a resistor and prevents waste of current.

The switch means may comprise a pair of contact members carried by the base which are engaged by depressing 'theswitc'h key. These contact members also act'as a reflector for the lamp for directing light through the switch 'key. Preferably, one of the contact members carries the switch key. Also, a springclip is preferably formed on one of the contact members forcarrying the lamp which is preferably of the baseless type.

Acover may also be carried by. the base and 3 Claims. (Cl. 200'167,)

ithas an opening through which the switch key extends. The switch key may be made of transparent vinyl plastic with its outer surface etched. In this way, a maximum amount-of diffused light is provided. The etched surface also provides means for readily receiving indicia, such as the name of the apartment or home owner or the like.

Further objects of this invention reside in the details of construction of the illuminated switch and the cooperative relationship between the component parts thereof.

Other objects and advantages will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawing in which- Fig. 1 is a perspective view of the illuminated switch of this invention;

Fig. 2 is a sectional view through the illuminated switch;

Fig. 3 is a plan view of the illuminated switch with the cover and switch key removed;

Fig. 4 is a sectional view taken along the'line 44 of Fig. 3;

Fig. 5 is an exploded perspective view of the contact members forming the switching means; and

Fig. 6 is a schematic wiring diagram showing the manner in which the illuminated switch of this invention may operate a doorbell or chimes.

Referring now to the drawing, the illuminated switch of this invention is generally designated at 10. It includes a base ll formed of suitable insulating material such as Bakelite. The base H on its underside is provided with a depression I2 and is provided at its ends with holes l3 for the purpose of mounting the base. The base is provided on its front face with a post l4 and a pair of ears i5. The sides of the base, as illustrated in Fig. 4, are provided with recesses Hi.

The base carries a switching means consisting of contact members 29 and ti! made of suitable electrical conducting material. The contact member 26 has a recess 21 for accommodating the post M of the base and isprovided at one end with a contact portion 22. The contact member 21] is also provided with a square 'hole'23 for'the purpose of securing'the same to the base H. .In this respect, a square rivet 24 extends through the square hole 23 of the contact member 20 and through a square hole in the base l. Thus, the contact member 20 is securely fastened to the base and rotation of the contact member is prevented. The contact-member is also provided wi h a ide fl e o m n a tow in lu 3 which is provided with a slot 26 for facilitating the soldering of a lead thereto.

The other contact member 30 is also provided with a recess 3| for accommodating the post I4 and is provided at its end with a contact portion 32. The contact portion 32 overlies the contact portion 22 but is normally spaced therefrom as is illustrated in Fig. 2. The contact member 30 is also provided with a square hole 33 for mounting purposes. A square rivet 34 extends through the square hole 33 and through a square hole in the base H. Thus, the contact member 30 is also securely mounted on the base I l and rotation of the same is prevented. It should also be noted that the two contact members and engage the ears l5 of the base H which further prevent rotation of these members on the base. The contact member 30 is also provided with a pair of upturned clip members 35 forming a clip for supporting a lamp as will be more fully pointed out hereafter. A soldering lug 36 is also formed on the contact member 30 and the soldering lug is provided with a slot 31 to facilitate soldering a lead thereto. The ends of the contact members 30 are provided with a pair of flanges 38 and 39.

A light transmitting switch key is designated at 40 and it is preferably made of a transparent vinyl plastic. It includes a top surface 4!, curved sides 42, and ends 43 and 44. The ends of the switch key are clamped by the flanges 3B and 39 of the contact member 30 and in this waythe switch key is carried by the contact member. The switch key 40 is provided with a post 45 and a coil spring 46 extends between the switch key 46 and the base I I and is held in position by the posts 14 and 45. The spring 46 urges the switch key 40 outwardly and hence operates resiliently to maintain the contact portions 22 and 32 separated. When, however, the switch key 40 is depressed against the action of the spring 46, the contact portion 32 engages the contact portion 22 for the purpose of closing a circuit.

The base also carries a cover 48. In this respect, the cover 48 is provided with indentations 49 adapted to be received in the recess [6 for the purpose of detachably securing the cover to the base. The cover is provided with an opening 50 through which the outer portion of the switch key 40 projects. The cover also limits the outward movement of the switch key.

The clip member 35 removably carries a lamp 52 beneath the switch key 40 for the purpose of illuminating the switch key. The lamp 52, because it is carried by the clip member 35, may be of the baseless type. Preferably, the lamp is a tungsten coiled-coil filament lamp having a coiled-coil tungsten filament 53. The characteristic of this lamp is such that it operates between l900 K. and 900 K. at voltages between 24 volts and 10 volts respectively. The lamp produces adequate light at 10 volts and still operates at a sufliciently low temperature at 24 volts to provide a calculated life of at least 10 years at such higher voltage. The lamp is provided with leads 54 which are connected to the soldering lugs 25 and 36. In this way, the lamp is connected in parallel to the contact members 20 and 30. External electrical connections are made to the contact members 20 and 30 and hence to the lamp 52 by means of screws 55 and 56 screw-threadedly received in the rivets 24 and 34.

Fig. 6 diagrammatically illustrates the manner of operation of the illuminated switch IU of this invention. In Fig. 6, the contact portions of the contact members are illustrated at 22 and 32 and the lamp is illustrated at 52. Power is supplied by a transformer generally designated at 60 including a primary 6| connected to the usual household voltage source and a secondary 62. A bell or chimes is designated at 63. The switching means 22, 32, the secondary 62, and the bell or chimes 63 are connected in series and the lamp 52 is connected in parallel with the switching means 22, 32. With the switching means open as illustrated in Fig. 6, the lamp 52 is in series with the bell or chimes 63, but the resistance of the lamp is sufficiently high to prevent operation of the bell or chimes 63 and to prevent waste of current. When, however, the switching means 22, 32 is closed, the lamp 52 is shunted and the bell or chimes 63 is operated.

Preferably, the upper face 4| of the transparent switching key 40 is etched so as to provide a maximum amount of diffused light. The etched surface also provides means for readily applying indicia such as the name of the apartment or home owner or the like. The lamp 52 in addition to illuminating the switch key also operates effectively to display the indicia.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. An illuminated switch comprising, an elongated base, switch means including a first contact member secured to the base and an elongated resilient second contact member also secured to the base, an elongated cover carried by the base and having an elongated opening therein, an elongated switch key of light transmitting material lying within the elongated opening of the cover and overlying and carried by the elongated second contact member for moving the contact members into engagement when the switch key is depressed, a spring clip on the elongated second contact member facing toward the switch key, a baseless lamp carried by the spring clip underneath the switch key for illuminating the switch key, and leads connecting the baseless lamp to the two contact members, the elongated second contact member acting as a reflector for the lamp.

2. An illuminated switch for operating an alarm from a transformer secondary comprising, an elongated base, switch means including a first contact member secured to the base and an elongated resilient second contact member also secured to the base, an elongated switch key of light transmitting material overlying and carried by the elongated second contact member for moving the contact members into engagement when the switch key is depressed for operating the alarm, a spring clip on the elongated second contact member facing toward the switch key, a baseless lamp carried by the spring clip underneath the switch key for illuminating the switch key, and leads connecting the baseless lam to the two contact members for illuminating the lamp when the contact members are separated, the elongated second contact member acting as a reflector for the lamp, said baseless lamp comprising a tungsten coiled-coil filament lamp operating below l900 K. at 24 volts.

3. An illuminated switch for operating an alarm from a transformer secondary comprising, a base, switch means including a first contact I member secured to the base and a second resilient contact member secured to the base and provided at its ends with a pair of flanges, one end of the second contact member adapted to be pressed into engagement with one end of the first contact member, a switch key of light transmitting material carried between the flanges of the second contact member for moving said ends of the contact members into engagement when the switch key is depressed for operating the alarm, a spring clip formed on one of the contact members, a baseless lamp carried by the spring clip underneath the switch key for illuminating the switch key, and leads connecting the lamp to the two contact members for illuminating the lamp when the contact members are separated, said baseless lamp comprising a tungsten coiled-coil filament 5 lamp operating below 1900 K. at 24 volts.

EDWARD V. SUNDT.

References Cited in the file of this patent UNITED STATES PATENTS 10 Number Name Date 2,234,954 Bergman Mar. 18, 1941 2,273,353 Harris Feb. 17, 1942 

